1. Field of the Invention
This invention relates to a tool for installing a pane to an existing glazing to provide an insulating, sealed airspace therebetween.
2. Discussion of the Technical Problem
U.S. Pat. No. 3,971,178 teaches a method of adding a pane to an existing glazing installation to provide an insulating, sealed airspace therebetween.
In general, the pane includes a spacer frame mounted on marginal edges of the pane by a moisture-impervious sealant. A moisture-impervious adhesive between the spacer frame and the existing glazing is flowed under pressure to form the insulated, sealed airspace between the pane and the existing glazing.
U.S. Pat. No. 3,971,178 in column 7, lines 54-61 teaches that pressure for flowing the adhesive may be applied by clamping facilities carried by glass holding equipment; by special leverage facilities coacting with the frame or wall structure; or to impose a vacuum in the newly created airspace for sufficient time to permit the moisture-impervious adhesive to flow and seal. Both the vacuum and mechanical facilities may be used simultaneously.
Although not specifically described, leverage facilities that have been used include a spreader bar having its ends mounted between opposing wall structure containing the glazing. A blade operatively connected to the spreader bar by way of a threaded shaft is positioned on the marginal edges of the pane. Rotating the threaded shaft urges the blade against the marginal edges of the pane of flow the adhesive between the spacer frame and glazing.
Although the above technique is acceptable, there are limitations. For example, applying a downward pressure on the blade to flow the adhesive applies an opposite force acting to move the spreader bar away from the pane. If the spreader bar is not secured in position, the spreader bar will move from between the wall structure. If too much pressure is applied by the spreader bar to the wall structure, the wall structure may be damaged.
It would be advantageous therefore to provide a tool for installing panes to existing glazing that does not have the limitations of the prior art spreader bar and blade assembly.